A number of devices exist that are able to remove suspended water, but not particulate matter from liquid and gaseous fuels. For example, in a fuel delivery system for a diesel fuel line, a supply tank is in fluid communication through conduits to a fuel injector, the fuel injector being in fluid communication with the engine for injecting fuel into the engine. Pumps are disposed between the fuel tank and injector for pumping fuel from the fuel tank to the injector. Generally, means are provided between the fuel tank and injector for filtering particulate matter from the fuel and for removing water from the fuel. There is also generally an overflow system for conducting overflow fuel from the injector back to the fuel tank.
A number of devices exist that are able to remove suspended water from fuels. Among these processes are coalescing devices and electro static percipitators. Dissolved water has been removed from hydrophobic liquids and gaseous with conventional processes that employ sorbents and desiccants. All of these conventional decontamination systems require maintenance. For example, the removal of suspended water from fuels is sometimes accomplished utilizing a coalescing device. These coalescing devices become filled with water during operation and must be maintained carefully to prevent water from being pumped with the fuel to the point of use.
Dissolved water can be removed from fuel streams using various water adsorbing media. The water adsorbing media must be discarded after the media becomes saturated with water or regenerated with the consumption of energy which adds to the cost of the process.
None of the aforementioned devices can remove suspended and dissolved water and dirt particles from fuels by themselves simultaneously.
Numerous types of filtration devices exist that can remove dirt particles from fuel streams but these filters eventually become clogged and must be replaced. Conventional filters intercept particulate matter and ultimately build up a filter cake that leads to a build up of back pressure to the extent that flow is restricted and the filter must be replaced. Conventional particle filters cannot remove suspended or dissolved water and possess a limited service life for particle removal.
These filters are commonly referred to as "dead end" filters because particle and water impact directly upon the filter media. The media acts as barrier, intercepting particles according to its design. These filters must balance particle holding capability and service life. A conventional filter with a relatively tight media will stop particles in the submicron range but possess a relatively short service life. Therefore, a trade-off must be made between service life and filter efficiency. The practical result is that the most efficient removal of particles is frequently not achieved. Moreover, relatively frequent change out of the filter device is necessary with conventional filters depending upon their particle holding efficiency. Often change-out is done after the filter has clogged and thereby represents a maintenance issue and a costly shut down of the assembly as well as the creation of uncertainty regarding possible damage to system parts due to filter failure. These type of filters present a variable of particle contamination and do nothing to prevent moisture problems.
The present invention provides means for effectively decontaminating a fuel of water and particulate material in a single pass. The present invention further provides a means of then removing dissolved water and dissolved water soluble components from either the fuel retentate flow or fuel permeate flow, all separation steps being accomplished in a single pass of the fuel flow through the separation devices. Accordingly, the present invention provides an extremely efficient means of providing a fuel decontaminated of water and particulate material as well as providing a means of deriving a fuel free water permeate.